Apart from that being fraud (marriage for the sole purpose of citizenship), getting married is not the top priority for most at that age.
Also, as part of the F-1 visa requirement they're required to demonstrate homeland ties that indicate there is a high chance they'll return after completing the course.
Not that easy. Most first-gen people I know are absolutely against marrying anyone who isn't a permanent resident, basically because of advice like yours.
Indian/Chinese men are much less desired than whites and sometimes blacks and latinos in the US dating market. Marrying an American is probably harder than alternative approaches, at least for males from these countries.
You could be the best and brightest or the dumb and dullest, won't matter.